Measuring the Cosmic X-ray Background accurately

Abstract

Synthesis models of the diffuse Cosmic X-ray Background (CXB) suggest that it can be resolved into discrete sources, primarily Active Galactic Nuclei (AGNs). Measuring the CXB accurately offers a unique probe to study the AGN population in the nearby Universe. Current hard X-ray instruments suffer from time-dependent background and cross-calibration issues. As a result, their measurements of the CXB normalization has an uncertainty of the order of ~15%. In this paper, we present the concept and simulated performances of a CXB detector, which could be operated on different platforms. With a 16-U CubeSat mission running for more than two years in space, such a detector could measure the CXB normalization with ~1% uncertainty.

The Cosmic X-ray Background explorer (CXBe)

“…The Cosmic X-ray Background explorer (CXBe) Nicolas Produit uncertainty after two years of observation, a very significant improvement [16].…”

“…Extremely low activity sources (200 Bq) are enough for this purpose and two tagged 241 Am sources will be attached beneath the bottom obturator for calibrations. Selecting coincident events in the spectrometers allows us to continuously characterize the detection efficiency and the Energy-Channel (EC) correlation of the detectors (details please refer to [16]).…”

Criminalisation of Traffic Hijacking and the Way Forward for Regulation

“…The company also developed traffic monetization software without authorization, and gave the company a share based on the number of advertisement clicks. In this case, the source code program involved in the case ran after the silent download and installation of a browser plug-in without the user's authorization, which is illegal control of the computer information system; However, a browser plug-in modifies the user's browser start-up page without the user's permission, against the user's will, which damages the original function of the user's computer information system [16]. The relationship between the two is the implication of means and ends, but the crime of illegal control a computer information system to evaluate the above-mentioned acts of the defendant unit is incomplete and incomplete.…”